This invention has to do with the production of interdiffusion alloy coatings such as are employed on high performance metal parts, including turbine vanes and blades, pump parts, and other parts subject to unusual demands for erosion, corrosion and wear resistance. More particularly, the invention relates to improvements in methods of producing such coatings on a wide variety of parts, which enables the rapid, repeatable obtention of superior performance parts of individually tailored properties through the selective inclusion, in a controlled interdispersion, of refractory oxide or hard carbide material and/or elemental metal additives, which are interdispersed, i.e. exist as discrete particulate material in the interdiffusion layer, with a high degree of control as to location, concentration, and, thereby, as to properties of the final product.
It is known to form intermetallic compounds and alloys on high performance parts such as turbine vanes and blades by subjecting the surface of the part to a diffusion of one or more constituents of a diffusion pack to form an interdiffusion layer, sometimes referred to as a diffusion coating. Typically, the pack comprises the one or several metals to be diffused, frequently aluminum, aluminum oxide, a halogen source and possibly other materials depending on the particular objective of the diffusion. The pack is heated for long periods at very high temperatures, and an intermetallic compound is formed typically both outwardly and inwardly of the part original surface. This kind of coating can lead extreme corrosion resistance properties to more easily formed, less costly metals, is renewable, and otherwise provides improved properties at lower overall cost.